GaN, which is a nitride semiconductor, has a band gap that causes blue light to be emitted. The band gap of the GaN may be controlled by forming a mixed crystal of the GaN using InN or AlN, for example. The GaN is therefore used as a semiconductor device for light emission, such as a blue light emitting diode or a laser diode.
Since the GaN has a dielectric strength higher than the dielectric strength of Si or GaAs, applicability of the GaN as a high-voltage semiconductor device, such as a high electron mobility transistor (HEMT), is also expected.